TORONTO ― The leader of Canada’s most left-wing political party vowed to stand up to President Donald Trump if elected prime minister and called on current Prime Minister Justin Trudeau to do the same.

“I believe that you have to stand up to a bully. You can’t back down from a bully ― that’s what they want you to do,” Jagmeet Singh, the recently elected leader of the New Democratic Party told HuffPost following Vermont Sen. Bernie Sanders’ speech on health care at the University of Toronto.

Trudeau has developed a close working relationship with the U.S. president since Trump took office in January, notwithstanding their major disagreements on issues like trade and immigrant rights. Trump appeared to get along well with Trudeau during the prime minister’s first visit to Washington, D.C., under the new presidency in February. Trudeau returned for renegotiation talks earlier this month among the U.S., Canada and Mexico on the North American Free Trade Agreement.

Trudeau praised Trump in June as someone who “knows how to interact socially on a very effective level.”

“I’ve always found that whenever he has made an engagement to me or a commitment to me on the phone or in person, he has followed through on that,” Trudeau said. “And that’s someone you can work with.”

Jagmeet Singh celebrates his win as leader of the New Democratic Party on Oct. 1. 2017. (Andrew Francis Wallace/Getty Images)

Singh was elected head of the New Democratic Party, or NDP, Canada’s most left-wing major party, on Oct. 1. If Singh remains leader of his party in two years, he will run for prime minister against Trudeau and the Conservative Party leader, a post currently held by Andrew Scheer. The next national elections are on Oct. 21, 2019.

Singh, a 38-year-old criminal defense attorney and member of Ontario’s provincial parliament, rose to international fame thanks to a viral video capturing him patiently reasoning with a xenophobic heckler at a town hall meeting.

In September, Singh, who is a practicing Sikh, was holding one of his “JagMeet and Greet” community forums in the Toronto suburb of Brampton when a woman began interrupting the event with anti-Muslim vitriol directed at Singh. (Practicing Sikh men, who typically wear turbans and grow large beards, are often subject to Islamophobic hate crimes and other prejudice based on the uninformed perception that they are Muslim.)

Singh encouraged the audience to chant “love and courage” to drown out her yells.

“We welcome you. We love you. We support you, and we love you,” he told the woman.

Even as he declared Sunday that he would adopt a confrontational stance toward Trump as prime minister, Singh advised Americans concerned about rising xenophobia and other forms of bias under Trump’s leadership to emulate the high-road approach he modeled at the town hall.

“We all need love and courage to tackle the issues of the day, to keep that love in your heart, that we’re all connected, we’re all in this together, and it requires courage for us to demand better, dream bigger and fight for a better world,” he told HuffPost. “That love and courage is a big part of why I do what I do, and I think that will motivate other people as well.”

Sen. Sanders arrived in Toronto on Saturday for a two-day tour of Canada’s publicly financed health care system. The trip was aimed at learning about its successes and challenges as he continues his push for the United States to adopt a similar system. On Saturday, Sanders visited several hospitals in downtown Toronto alongside Ontario Premier Kathleen Wynne of the Liberal Party, several American medical professionals and Canadian physicians and health care advocates.

Wynne introduced Sanders on Sunday ahead of his speech to an audience of over 1,000 people, most of them University of Toronto students.

But in keeping with its role as the most ardent proponent of universal health care in Canadian history, the NDP got its fair share of the limelight.

In his speech, Sanders sang the praises of Tommy Douglas, who was the first leader of the NDP and is credited as the forefather of Canada’s national health care system. The party is now fighting for universal coverage of pharmaceutical drugs, which the government does not guarantee across the board, as well as dental care, which is entirely private. (Wynne said she also supports universal pharmaceutical coverage, and has overseen the expansion of Ontario’s health insurance program to cover pharmaceutical drugs for all provincial residents from birth through age 24, which will take effect in January.)

And aside from Sanders, Singh was clearly a crowd favorite, drawing raucous applause when he entered the room and took his seat in the front row.

Speaking after Sanders, Ed Broadbent, who led the NDP from 1975 to 1989, gave Singh a shout-out.

A bill the NDP introduced in parliament that would provide universal pharmaceutical coverage, Broadbent noted, “didn’t pass, but I can tell you the struggle for it will continue.”

“And I also want you to know that it pleases me a lot that the man who will lead that battle is Jagmeet Singh,” he added.

The applause at the mention of Singh’s name was so loud that he stood up and waved to acknowledge the ovation.

Singh met with Sanders on Sunday morning prior to his speech, a conversation Singh described as “awesome.” He asked Sanders what motivated him to fight so hard for universal health care.

“He just said, ‘It makes sense.’ Health should be a human right,” Singh recalled. “And I was really touched by that. I think it’s absolutely true. It’s something that the New Democrats believe as well. It’s something I really believe in.”

Correction: An earlier version of this story referred to the New Democratic Party as the National Democratic Party.